There are myriad applications which require the capability to obtain information about the frequency of a periodic signal. Conventional frequency-to-current conversion circuits produce an output current that represents the frequency of an input periodic signal, and conventional frequency-to-voltage conversion circuits produce an output voltage that represents the frequency of an input periodic signal. These, conventional approaches typically use a feed-back loop to synchronize the output signal to the frequency of the periodic input signal. The feed-back loop requires a certain amount of locking time to lock the output signal representation to the frequency of the input signal. This locking time can present difficulties in some situations, for example, when the frequency of the input signal abruptly changes by a relatively large amount.
It is desirable in view of the foregoing to provide for an output signal representation of an input signal frequency while also avoiding the locking time associated with the operation of conventional feed-back control loops.